It contains an uninitialized variable read, sorry. It needs reverting and replacing with the patch that will be attached.
Created attachment 4132 [details]
patch for 3.3
Ok, I've studied this very carefully and the logic is pretty clear in what it's trying to do, I'm ok with this for 3.3. I don't see what the uninitialized variable read you are fixing was though, sorry. Could you explain that a little more ?
The variable "mangled" in get_real_filename() is uninitialized. Even gcc complains about it. I missed that, which kindof sucks....